Electrolyte and method for electrodepositing of bright nickel-iron alloy deposits

ABSTRACT

An aqueous bath suitable for the electrodeposition of a bright iron nickel electrodeposit onto a substrate susceptible to corrosion comprising iron ions, nickel ions, a bath soluble complexing agent containing at least two complexing groups, said groups independently selected from the group consisting of carboxy and hydroxy, providing at least one group is a carboxy group; the bath having a pH from 2.5 to about 5.5 and containing a sulfide.

United States Patent [1 1 Tremmel Apr. 15, 1975 54] ELECTROLYTE AND METHOD FOR 2,978,391 4/1961 Du Rose 204/49 ELECTRODEPOSITING OF BRIGHT NICKEL-IRON ALLOY DEPOSITS Robert Arnold Tremmel, Woodhaven, Mich.

Oxy Metal Finishing Corporation, Warren, Mich.

Filed: Nov. 8, 1973 Appl. No.: 414,003

Related U.S. Application Data Continuation-impart of Set. No. 268,352, July 3, 1972, abandoned.

Inventor:

Assignee:

References Cited UNITED STATES PATENTS 6/1959 Gundel et al. 204/49 X 3,276,979 10/ i966 Strauss et al 204/49 Primary Examiner-G. L. Kaplan Attorney, Agent, or Firm-B. F. Claeboe [5 7 ABSTRACT An aqueous bath suitable for the electrodeposition of a bright iron nickel electrodeposit onto a substrate susceptible to corrosion comprising iron ions, nickel ions, a bath soluble complexing agent containing at least two complexing groups, said groups independently selected from the group consisting of carboxy and hydroxy, providing at least one group is a carboxy group; the bath having a pH from 2,5 to about 5.5 and containing a sulfide.

40 Claims, No Drawings ELECTROLYTE AND METHOD FOR ELECTRODEPOSITING OF BRIGHT NICKEL-IRON ALLOY DEPOSITS CROSS REFERENCE TO RELATED CASES This application is a continuation-inpart of application Ser. No. 268,352 filed July 3, 1972, now abandoned.

BACKGROUND OF THE INVENTION For many years electrodeposited nickel has been used as a substrate for the electrodeposition of chromium in order to impart satisfactory corrosion resistant properties to a metallic surface. Attempts have been made to obtain various alloys of nickel in order to decrease the cost of obtaining satisfactory decorative finish. Iron nickel deposits have been used previously for the electrodeposition of electromagnetic films. These films are usually extremely thin surfaces and normally are not decorative in character or exposed to corrosive environments. Application Ser. No. 268,348 filed July 3, 1972, now abandoned and of which application Ser. No. 380,631 filed July 19, 1973, now US. Pat. No. 3,806,429 is a continuation-in-part, describe various means of obtaining nickel iron electrodeposits.

SUMMARY OF THE INVENTION In the electrodeposition of iron nickel alloy deposits, it has been found that dull areas may be obtained in low current density areas. In order to obtain desirable bright iron-nickel deposits with good leveling and ductility with satisfactory corrosion resistant properties, it has been found that organic sulfides may be added to an iron-nickel alloy bath containing ions of both iron and nickel, and an iron complexing agent containing complexing groups such as carboxy and hydroxy groups. When such a bath is used for the electrodeposition of iron-nickel alloys in conjunction with a bath soluble nickel brightener, a bright iron nickel alloy deposit is obtained.

DESCRIPTION OF PREFERRED EMBODIMENTS Applicants invention is directed to the electrodeposition of a bright iron-nickel alloy deposit of from 5 to 50 percent by weight iron preferably about to about 35% by weight which can be used as the basis for subsequent electrodeposition of chromium in order to impart desirable decorative and/or corrosion resistant properties to substrates, such as metallic substrates.

The bath and process of the present invention can also be used in the electrodeposition of nickeLiron alloy for plastics. Normally the plastic substrate such as, acrylonitrile-butadiene-styrene, polyethylene, polypropylene, polyvinyl chloride, phenol-formaldehyde polymers is pretreated by applying a conductive metallic deposit onto the plastic substrate such as, nickel or copper. The iron-nickel deposit may then be used as a subsequent coating onto the conductive metallic deposit.

The bath that may be employed in the present invention utilizes one or more salts of nickel, one or more salts of iron, and a complexing agent.

In order to introduce iron and nickel ions into the bath, any bath soluble iron or nickel containing compound may be employed providing the corresponding anion is not detrimental to the bath. Preferably inorganic nickel salts may be employed, such as, nickel sulfate, nickel chloride, and the like as well as other nickel materials such as nickel sulfamate and the like. When nickel sulfate salts are used they are normally present in amounts ranging from 40 to 300 grams/liter (calculated as nickel sulfate 6I-I O); nickel chloride may also be used and is present in an amount ranging from about to 250 grams/liter. The chloride or halide ions are employed in order to obtain satisfactory conductivity of the solution and at the same time to obtain satisfactory corrosion properties of the soluble anodes.

Preferably' the inorganic salts of iron are employed, such as, ferrous salts, such as, ferrous sulfate, ferrous chloride, and the like. These salts are present in an amount ranging from about 3 to 60 grams/liter. Other bath soluble iron salts may be employed, such as, soluble ferrous fluo'borate, or sulfamate, and the like. The bath 'should contain not less than about 10 g/l of nickel plus ferric and ferrous ions.

The iron complexing agent that is employed in the present invention is one that is bath soluble and contains complexing groups independently selected from the group consisting of carboxy and hydroxy providing at least I of the complexing groups is a carboxy group and further providing that there are at least two complexing groups. The complexing agent that may be employed is present in amount ranging from about 10 to about grams/liter. Suitable complexing agents are hydroxy substituted lower aliphatic carboxylic acids having from 2 to 8 carbon atoms, from 1 to 6 hydroxy] groups and from 1 to 3 carboxyl groups such as, ascorbic acid, isoascorbic acid, citric acid, malic acid, gluteric acid, gluconic acid, muconic, glutamic, gluheptonate, glycollic acid, aspartic acid and the like as well as amine containing complexing agents, such as nitrilotriacetic acid, ethylene diamine tetra-acetic acid, as well as the water soluble salts thereof such as ammonium and the alkali metal salts such as potassium, sodium, lithium, and the like. It can also be appreciated that the iron may be introduced into the bath as a salt of the complexing agent.

By carboxy is meant the group-COOH. However, it is to be appreciated that in solution, the proton disassociates from the carboxy group and therefore this group is to be included in the meaning of carboxy.

The purpose of the complexing agent is to keep the metal ions, in particular, the ferrous and ferric ions in solution. It has been found that as the pH of a normal Watts nickel plating bath increases above a pH of 3.0, ferric ions tend to precipitate as ferric hydroxide. The complexing agent will prevent the precipitation from taking place and therefore makes the iron and nickel ions available for electrodeposition from the complexing agent.

Because of the operating parameters employing the complexing agent, the pH of the bath preferably ranges from about 2.5 to about 5.5 and even more preferably about 3 to about 3.5.

The temperature of the bath may range from about F to about 180F preferably about F.

The average cathode current density may range from about 10 to about 70 amps sq. ft. preferably about 45 amps sq. ft.

It is preferred that the complexing agent concentration should be at least three times the total iron ion concentration in the bath. The complexing agent concentration ratio to total iron ion concentration may range from 3 to 50:1.

The bath may also contain various buffers such as boric acid and sodium acetate and the like ranging in amounts from about 30 to 60 grams/ liter, preferably 40 grams/liter. The ratio of nickel ions to iron ions ranges from about 5 to about 50 to 1.

While the bath may'be operated without agitation, various means of agitation may be employed such as mechanical agitation, air agitation, cathode rod movement and the like.

It has been found that various nickel brightening additives may be employed to impart brightness, ductility and leveling to the iron nickel deposits. Suitable additives are the sulfo oxygen compounds as are described as brighteners of the first class described in Modern Electroplating, published by John Wiley and Sons, second edition, page 272.

The amount of sulfo-oxygen compounds employed in the present invention ranges from about 0.5 to about g/l. It has been found that saccharin may be used in amounts ranging from 0.5 to about 5 g/l resulting in a bright ductile deposit. When other sulfo-oxygen compounds are employed, such as, naphthlenetrisulfonic, sulfobenzaldehyde, dibenzenesulfonamide, good brightness is obtained but the ductility is not as good as with saccharin. In addition to the above sulfo-oxygen compounds that may be used, others are sodium allyl sulfonate, benzene sulfinates, vinyl sulfonate, Betastyrene sulfonate, cyano alkane sulfonates (having from 1 to 5 carbon atoms).

The bath soluble sulfo-oxygen compounds that may be used in the present invention are those such as the unsaturated aliphatic sulfonic acids, mononuclear and binuclear aromatic sulfonic acids, mononuclear aromatic sulfinic acids, mononuclear aromatic sulfonamides and sulfonimides, and the like.

It has also been found that acetylenic nickel brighteners may also be used in amounts ranging from about 10 to about 500 mg/l. Suitable compounds are the acetylenic sulfo-oxygen compounds mentioned in U.S. Pat. No. 2,800,440. These nickel brighteners are the oxygen containing acetylenic sulfo-oxygen compounds. Other acetylenic nickel brighteners are those described in U.S. Pat. No. 3,366,557 such as the polyethers resulting from the condensation reaction of acetylenic alcohols and diols such as, propargyl alcohol, butyndiol, and the like and lower alkylene oxides such as, epichlorohydrin, ethylene oxide, propylene oxide and the like.

It has also been found that nitrogen heterocyclic quaternary or betaine nickel brighteners may also be used in amounts ranging from about I to about 50 mg/l. Suitable compounds are those nickel brighteners described in U.S. Pat. No. 2,647,866 and the nitrogen heterocyclic sulfonates described in U.S. Pat. No. 3,023,151. Preferred compounds described therein are the pyridine quaternaries or betaines or the pyridine sulfobetaines. Suitable quaternaries that may be employed are quinaldine propane sultone, quinaldine dimethyl sulfate, quinaldine allyl bromide, pyridine allyl bromide, isoquinaldine propane sultone, isoquinaldine dimethyl sulfate, isoquinaldine allyl bromide, and the like.

At times the low current density areas are not fully ing bath composition. These organic sulfides are of the formula;

l R -N=C-S-R where R is hydrogen or a carbon atom of an organic radical, R is nitrogen or a carbon atom of an organic radical and R is a carbon atom of an organic radical. R and R or R may be linked together through a single organic radical.

More specifically, the bath soluble organic sulfide compounds used are 2-amino thiazoles and isothioureas having the formulae:

R4-C-N II II R -C C-NH-R6 and ' c-s-R R-N 8 H wherein R is selected from H, lower alkyl sulfonic acid groups, aryl sulfonic acid groups, lower alkoxy aryl sulfonic acid groups and the salts thereof; R and R are selected from H, halogen, lower alkyl groups and the bivalent radical 1o l c in which R is H, halogen or lower alkyl groups and n is 0 or 1, the R groups being selected from H, halogen and lower alkyl groups; R,, is selected from lower alkyl sulfonic acid groups and lower alkyl carboxy acid groups and the salts thereof; and R, and R are selected from H, halogen, lower alkyl groups and the bivalent radical in which the R and R, groups are selected from H, halogen and lower alkyl groups, n is 0 or 1, and providing that when n=0, the bivalent radical form a six membered ring when R, and R are joined and a five membered ring when R, and R are joined.

It is to be appreciated that in referring to halogens, it is intended to include chlorine, bromine, fluorine and iodine, although chlorine is generally preferred. Moreover, where reference is made to lower alkyl or alkoxy groups, it is intended to include groups containing from about 1 to 6 carbon atoms in a straight or branched chain, with from about 1 to 4 carbon atoms being preferred. Additionally, in referring to the sulfonic or carboxy acids and their salts, it is intended to include those sulfonic and carboxy acids which have halogen substituents on their alkyl, alkoxy or aryl groups and wherein TABLE I (3) HC-N a N (CH -S0 Na (6) I-lzC-N Compound (1), 2-aminothiazole and compound (2), 2-aminobezothiazole can be reacted with bromoethane sulfonate, propane sultone, benzyl chloride, dimethylsulfate, diethyl sulfate, methyl bromide, propargyl bromide, ethylene dibromide, allyl bromide, methyl chloro acetate, sulfophenoxyethylene bromide, the latter, for example, can be reacted with compound (1) to give compound (3), etc., to form compounds that give even improved results over compounds (1) and (2). Also, substituted 2-aminothiazoles and 2- amionbenzothiazoles, such as 2-amino-5- chlorothiazole, 2-amino-4-methylthiazole, etc., can be used instead of compounds (1) and (2). To form compounds such as (5) and (6), thiourea can be reacted with propiolactone, butyrolactone, chloroacetic acid, chloropropionic acid, propane sultone, dimethyl sulfate, etc. Also, phenyl thiourea, methyl thiourea, allyl thiourea and other similar substituted thiourea may be used in the reactions to form compounds similar to types (5) and (6).

It is to be appreciated that the above nickel brighteners must be soluble in the electroplating bath and may be introduced into the bath, when an acid is involved, as the acid itself or as a salt having bath soluble cations,

Concentration Range (grams liter) such as ammonium ions or the alkali metal ion, such as, lithium, potassium, sodium, and the like.

It has been found that the use of bright nickel iron deposits of about 20 to 45% iron content function as well or better than bright nickel deposits in certain compos ite electroplate systems.

In particular, relatively thin coatings of bright nickel iron having less than about 0.5 mil thickness (such as 0.1 mil thickness) with an alloy content of about 20 to 45% iron, function more effectively than an equivalent bright nickel coating when copper or brass undercoats are employed. In particular, if the iron content is about 35% or more, the alloy deposits corrode more preferentially to copper or brass undercoats than does bright nickel. This action delays penetration to the basis metal.

These bright nickel iron coatings also function well as the thin top coat on semi-bright sulfur free nickel deposits. The bright nickel iron is very effective in such a composite electroplate when overplated with micro discontinuous chromium coatings such as that described in U.S. Pat. Nos. 3,563,864 and 3,151,971-3. The microdiscontinuous chromium coatings may be achieved by thin nickel deposits which induce microporosity or micro-cracking in the chromium or by plating the chromium deposit from a specific solution which deposits a microcracked chromium.

It can be appreciated that the nickel salts may be substituted with minor amounts up to 50% of the nickel salts with cobalt salts in order to achieve different corrosion behavior.

A suitable composition that may be employed in the present invention is as follows:

Cathode current density average 25 to 55 amps. sq. ft.

anode current 10-20 ASF density temperature l40F to l60F pH 2.5 to 5.5 3.0-4.2 agitation air or rod brightener see above It is to be appreciated that various other additives may be employed to effect desirable results such as, surface active agents tov overcome any undesirable problems that may occur in particular situations such as pitting.

When significant amounts of iron are being introduced into the system, it has been found that soluble iron anodes or nickel-iron alloy anodes should be employed. The ratio of nickel to iron in the anode area should be maintained at approximately 4 to l. Preferably dual (nickel and iron) anodes are used and the iron anodes should be insulated from a direct contact to the anode rail and connected subsequently to the anode rail through a highly electrically resistant device such as a nickel-chrome wire or controlled by a separate rheostate to maintain a total current to the iron anodes of about 8 to 30% preferably about 10 to 25% of the total anode current. Anode bags, filter bags, hoses, tank linings etc. should be those which are generally employed in other bright nickel processes.

EXAMPLE No. l

A bright iron nickel bath was formulated as follows:

50 g/l Nickel sulfate hexahydrate I g/l Nickel chloride hexahydrate l g/l Ferrous sulfate heptahydrate 26 g/l Ammonium hydrogen citrate 60 g/l Boric acid Temp. l50F Agitation Rod 4.5 g/l Saccharin 3.75 g/l Allyl sulfonate 200 mg/l Butyne diol ethylene oxide (ratio 1.8 moles oxide: l mole diol) mg/l Quinaldine propane sultone Rolled steel panels were plated at 45 ASF and gave full bright lustrous ductile deposits containing 15-20% iron.

EXAMPLE NO. 2

Following the procedure of Example No. l but containing; 7.5 g/l glycine instead of citrate resulted in the formation of an insoluble complex. No acceptable nickel-iron deposit was obtained.

EXAMPLE No. 3

Another nickel-iron bath was formulated as follows:

75 g/l Nickel sulfate hexahydrate 75 g/l Nickel chloride hexahydrate 15 g/l Ferrous sulfate heptahydrate 40 g/l Sodium gluconate 40 g/l Boric acid Temp. l50F Agitation Air 2.5 g/l Saccharin 6.0 g/l Allyl sulfonate 50 mg/l Glycerol ether of butyne diol (adduct of 1.8 moles ethylene oxide: l mole diol) 50 mg/l Glycerol ether of butyne diol sulfonated. (same as above adduct) except product is sulfonated.

15 mg/l Adduct of 1.8 moles epichlorohydrinzl mole propargyl alcohol; product is sulfonated.

215 mg/l Thiourea-S-acetic acid A test panel (J-steel) plated from this bath gave a bright level deposit with excellent ductility and clean recess areas.

The iron content of the plated deposit was approximately 20-25%.

EXAMPLE NO. 4

A nickel-iron plating bath having a high iron concentration was tested in a pilot plating laboratory. The composition of the bath was as follows:

Ni 42.0 g/l NiCl .6H,0 100.5 g/l NiSO .6H,0 76.6 g/l H 36.0 g/l Na Gluconate 65.0 g/l Fe total 5.8 g/l Saccharin 2.5 g/l Allyl sulfonate 6.0 g/l Glycerol ether of butyne diol (See example No. 3) 0.05 g/l Glycerol ether butyne diol sulfonated (see example No. 3) 0.05 g/l adduct of ethylene oxide and propargyl alcohol 0.012 g/l pH 3.0 Temp. l55F A J-type steel panel plated at 50 ASP was overall bright, leveled, very ductile, with a part skipped recess area.

0.002 g/l of dithio dipropane sulfonate was added to the bath and another panel was plated. The resulting deposit was again overall bright, leveled and ductile; however, now the recess areas were clean, covered and bright.

The iron included in these deposits was approximately 38-47%.

EXAMPLE No.5

A bath was formulated as follows:

Fe total 3.11 g/l Fe 2.83 g/l Fe 0.22 g/l allyl sulfonate 4.5 g/l saccharin 3 g/l Butyncdiol ethylene oxide adduct (1:1.8 mole ratio) 200 mg/l Quin-aldine propane sultonc mg/l Ni Cl .6H O 101.8 g/l Ni sn,.6H,o 122.7 g/l Ni 52.6 g/l Boric acid 59.1 g/l diammonium citrate 26.8 g/l pH 4.0 Temp. 150F Agitation cathode or rod A J-shaped panel was plated at 40 ASF and obtained was a full bright lustrous deposit in the high current density area and a low current density cloud.

Addition of only 50 mg/l of benzene sulfinate removed the recess cloud completely. The deposits contained 17.5% Fe.

EXAMPLE No. 6

Two nickel-iron plating solutions were prepared having the following compositions.

NiCl .6H O 75 g/l NiSO .6l-| O 75 g/l FeSO, g/l 3B0: 40 g/ l Na Gluconate 12.5 g/l Na Citrate 12.5 gll Saccharin 3 0 g/l Allyl sulfonate 6.0 g/l adduct of butyne diol and epichlorohydrin 1.2 moles hydrin: 1 mole diol); product hydrolyzed 0.06 g/l adduct of butyne diol and epichlorohydrin 1.2 moles hydrin: 1 mole diol); product sulfonated 0.06 g/l adduct of propargyl alcohol and epichlorohydrin (1:1 mole ratio); product sulfonatecl 0.02 g/l dithiodipropane sulfonate 0.002 g/l Temp. 160F Agitation Air B.

NiCl .6H- O 75 g/l NiSO .6H O 75 g/l FeSO.,.7H O 15 g/l HsBOa 40 g/l Na Gluconate 12.5 g]! NH Citrate 12.5 g/l Saccharin 3.0 g/l Allyl sulfonate 6.0 g/l adduct of butyne diol and epichlorohydrin 1.2 moles hydrin: 1 mole diol); product hydrolyzed 0.06 g/l adduct of butyne diol and epichlorohydrin 1.2 moles hydrin: 1 mole diol); product sulfonated 0.06 g/l adduct of propargyl alcohol and epichlorohydrin 1:1 mole) ratio); product sulfonated 0.02 g/l dithiodipropane sulfonate 0.002 g/l Temp. 160F Agitation Air Test panels were plated from each solution for 10 minutes at 45 ASF. Results showed both deposits to be overall bright with clean recess areas, with panel A having better leveling than panel B. Both panels had excellent ductility.

As can be seen in example No. 6 a plurality of complexing agents may be used to obtain desirable results. It has also been determined that the gluconate complexing agent tends after long periods of electrolysis to form insoluble materials such as nickel salt of a gluconate degradation product. To continue to obtain desirable resultsa combination of complexing agents may be employed, such as, citrate and gluconate.

What is claimed is:

1. An aqueous bath suitable for the electrodeposition of a bright iron-nickel electrodeposit onto a substrate susceptible to corrosion comprising not less than about 10 grams per liter nickel plus ferric and ferrous ions, the ratio of nickel ions to ferric and ferrous ions being from about 5 to about 50 to l, 0.5 to 10 g/l of a bath soluble organic primary nickel brightener of the first class containing a sulfo-oxygen group, an amount of a bath soluble complexing agent effective to keep substantially all of the ferric and ferrous ions in solution and containing at least two complexing groups, said groups being independently selected from the group consisting of carboxy and hydroxy, provided at least one group is a carboxy group; the bath having a pH from about 2.5 and about 5.5 and 0.5 to 40 mg/l of an organic sulfide of the formula:

c- S-R3 and isothioureas having the structure:

wherein R is selected from H, lower alkyl sulfonic acid groups, aryl sulfonic acid groups, lower alkoxy aryl sulfonic acid groups and the salts thereof:

R and R are selected from H, halogen, lower alkyl groups and the bivalent radical in which R is H, halogen or lower alkyl groups and n is 0 or 1, the R groups being selected from H, halogen and lower alkyl groups, R is selected from lower alkyl sulfonic acid groups and lower alkyl carboxy acid groups and the salts thereof; and R and R are selected from H, halogen, lower alkyl groups and the bivalent radical in which the R and R, groups are selected from H, halogen and lower alkyl groups, n is O or 1, and providing that when n O, the bivalent radicals form a six membered ring when R and R are joined and a five membered ring when R and R are joined.

3. The bath of claim 2 wherein the complexing agent is an aliphatic carboxylic acid having from 1 to 3 carboxyl groups, 2 to 8 carbon atoms, and l to 6 hydroxyl groups.

4. The bath of claim 2 wherein the complexing agent is citric acid.

5. The bath of claim 2 wherein the complexing agent is gluconic acid.

6. The bath of claim 2 wherein R and R are hydrogen.

7. The bath of claim 2 wherein R is lower alkyl sulfonic acid.

8. The bath of claim 2 wherein R is lower alkoxy aryl sulfonic acid.

9. The bath of claim 2 wherein R is lower alkyl sulfonic acid.

10. The bath of claim 2 wherein R is lower alkyl carboxy acid and salts thereof.

11. The bath of claim 2 wherein the organic sulfide is 2-aminothiazole in a concentration of about 0.001 to 0.005 grams/liter.

12. The bath of claim 2 wherein the organic sulfide is isothiourea-s-propionic acid in a concentration of about 0.001 to 0.010 grams/liter.

13. The bath of claim 2 wherein the organic sulfide is a compound of the formula:

Ii HC Na 3 ..:"L.

in a concentration of 0.001 to 0.060 grams/liter.

14. The bath of claim 1 wherein the ratio of nickel ions to iron ions in the bath ranges from about 5 to about 50 to 1; and the ratio of complexing agent to iron ion concentration ranges in the bath from about 3 to about 50 to l.

15. The bath of claim 1 wherein the total iron ions are present in an amount ranging from about 5 to 40 g/l, calculated as FeSO .7H O; nickel sulfate present in an amount ranging from about 40 to 300 g/l, calculated as nickel sulfate.6H O; nickel chloride hexahydrate present in an amount from about 80 to 250 g/l and the complexing agent is present in an amount from about 10 to 100 g/l.

16. The bath of claim 1 wherein the complexing agent contains an amino group.

17. The bath of claim 1 wherein the sulfo-oxygen brightener is saccharin.

18. The bath of claim 1 further comprising an acety- 12 lenic nickel brightener present in an amount ranging from about 10 to 500 mg/l.

19. The bath of claim 1 further comprising a quaternary nitrogen heterocyclic nickel brightener present in an amount ranging from about 1 to about 50 mg/l.

20. The bath of claim 1 wherein R is hydrogen and R is nitrogen of an organic radical.

21. A process for producing a bright iron nickel alloy electrodeposit comprising passing a current through the bath of claim 1 and electrodepositing an iron nickel alloy containing about from 5 to about 50% iron onto a cathodic surface.

22. A process of claim 21, wherein the organic sulfide is selected from the group consisting of an amino thiazole of the structure:

and isothioureas having the structure:

wherein R is selected from H, lower alkyl sulfonic acid groups, aryl sulfonic acid groups, lower alkoxy aryl sulfonic acid groups and the salts thereof;

R and R are selected from H, halogen, lower alkyl groups and the bivalent radical F10 C I in which R, is H, halogen or lower alkyl groups and n is O or 1, the R groups being selected from H, halogen and lower alkyl groups, R is selected from lower alkyl sulfonic acid groups and lower alkyl carboxy acid groups and the salts thereof; and R and R are selected from H, halogen, lower alkyl groups and the bivalent radical in which the R and R groups are selected from H, halogen and lower alkyl groups, n is 0 or 1, and providing that when n O, the bivalent radicals form a six membered ring when R, and R are joined and a five membered ring when R and R are joined.

23. The process of claim 22'wherein R and R are hydrogen.

24. The process of claim 22 wherein R is lower alkyl sulfonic acid.

25. The process of claim 22 wherein R is lower alkyl carboxy acid and salts thereof.

26. The process of claim 21 wherein the ratio of nickel ions to iron ions in the bath ranges from about 5 to about 50 to 1; and the ratio of complexing agent to iron ion concentration ranges in the bath from about 3 to about 50 to l.

27. The process of claim 21 wherein the total iron ions are present in an amount ranging from about 5 to 40 g/l, calculated as FeSO .7H O; nickel sulfate present in an amount ranging from about 40 to 300 g/l, calculated as nickel sulfate.6H O; nickel chloride hexahydrate present in an amount from about 80 to 250 g/l and the complexing agent is present in an amount from about to 100 g/l.

28. The process of claim 21 wherein the complexing agent is an aliphatic carboxylic acid having from 1 to 3 carboxyl groups, 2 to 8 carbon atoms, and l to 6 hydroxyl groups.

29. The process of claim 21 wherein the complexing agent contains an amino group.

30. The process of claim 21 wherein the complexing agent is citric acid.

31. The process of claim 21 wherein the complexing agent is gluconic acid.

32. The process of claim 21 wherein the sulfo-oxygen brightener is saccharin.

33. The process of claim 21 further comprising an acetylenic nickel brightener present in an amount ranging from about 10 to 500 mg/l.

34. The process of claim 21 further comprising a quaternary nitrogen heterocyclic nickel brightener present in an amount ranging from about 1 to about 50 mg/l.

35. The process of claim 21 wherein R is hydrogen and R is nitrogen of an organic radical.

36. The process of claim 21 wherein R is lower alkyl sulfonic acid.

37. The process of claim 22 wherein R is lower alkoxy aryl sulfonic acid.

38. The process of claim 21 wherein the organic sulfide is 2-aminothiazole in a concentration of about 0.001 to about 0.005 grams/liter.

39. The process of claim 21 wherein the organic sulfide is isothiourea-s-propionic acid in a concentration of about 0.001 to about 0.010 grams/liter.

40. The process of claim 21 wherein the organic sulfide is a compound of the formula:

HC H

II n HC C- N-C2H40 -S0 Na 

1. AN AQUEOUS BATH SUITABLE FOR THE ELECTRODEPOSITION OF A BRIGHT ITON-NICKEL ELECTRODEPOSIT ONTO A SUBSTRATE SUSCEPTIBLE TO CORROSIION COMPRISING NOT LESS THAN ABOUT 10 GRAMS PER LITER NICKEL PLUS FERRIC AND FERROUS IONS, THE RATIO OF NICKEL IONS TO FERRIC AND FERROUS IONS BEING FROM ABOUT 5 TO ABOUT 50 TO 1, 0.5 TO 10 G/L OF A BATH SOLUBLE ORGANIC PRIMARY NICKEL BRIGHTENER OF THE FIRST CLASS CONTAINING A SULFO-OXYGEN GROUP, AN AMOUNT OF A BATH SOLUBLE COMPLEXING AGENT EFFECTIVE TO KEEP SUBSTANTIALLY ALL OF THE FERRIC AND FERROUS IONS IN SOLUTION AND CONTAINING AT LEAST TWO COMPLEXING GROUPS, SAID GROUPS BEING INDEPENDENTLY SELECTED FROM THE GROUP CONSISTING OF CARBOXY AND HYDROXY, PROVIDED AT LEAST ONE GROUP IS A CARBOXY GROUP; THE BATH HAVING A PH FROM ABOUT 2.5 AND ABOUT 5.5 AND 0.5 TO 40 MG/L OF AN ORGANIC SULFIDE OF THE FORMULA:
 2. The bath of claim 1, wherein the organic sulfide is selected from the group consisting of an amino thiazole of the structure:
 3. The bath of claim 2 wherein the complexing agent is an aliphatic carboxylic acid having from 1 to 3 carboxyl groups, 2 to 8 carbon atoms, and 1 to 6 hydroxyl groups.
 4. The bath of claim 2 wherein the complexing agent is citric acid.
 5. The bath of claim 2 wherein the complexing agent is gluconic acid.
 6. The bath of claim 2 wherein R5 and R6 are hydrogen.
 7. The bath of claim 2 wherein R3 is lower alkyl sulfonic acid.
 8. The bath of claim 2 wherein R3 is lower alkoxy aryl sulfonic acid.
 9. The bath of claim 2 wherein R9 is lower alkyl sulfonic acid.
 10. The bath of claim 2 wherein R9 is lower alkyl carboxy acid and salts thereof.
 11. The bath of claim 2 whereIn the organic sulfide is 2-aminothiazole in a concentration of about 0.001 to 0.005 grams/liter.
 12. The bath of claim 2 wherein the organic sulfide is isothiourea-s-propionic acid in a concentration of about 0.001 to 0.010 grams/liter.
 13. The bath of claim 2 wherein the organic sulfide is a compound of the formula:
 14. The bath of claim 1 wherein the ratio of nickel ions to iron ions in the bath ranges from about 5 to about 50 to 1; and the ratio of complexing agent to iron ion concentration ranges in the bath from about 3 to about 50 to
 1. 15. The bath of claim 1 wherein the total iron ions are present in an amount ranging from about 5 to 40 g/l, calculated as FeSO4.7H2O; nickel sulfate present in an amount ranging from about 40 to 300 g/l, calculated as nickel sulfate.6H2O; nickel chloride hexahydrate present in an amount from about 80 to 250 g/l and the complexing agent is present in an amount from about 10 to 100 g/l.
 16. The bath of claim 1 wherein the complexing agent contains an amino group.
 17. The bath of claim 1 wherein the sulfo-oxygen brightener is saccharin.
 18. The bath of claim 1 further comprising an acetylenic nickel brightener present in an amount ranging from about 10 to 500 mg/l.
 19. The bath of claim 1 further comprising a quaternary nitrogen heterocyclic nickel brightener present in an amount ranging from about 1 to about 50 mg/l.
 20. The bath of claim 1 wherein R1 is hydrogen and R2 is nitrogen of an organic radical.
 21. A process for producing a bright iron nickel alloy electrodeposit comprising passing a current through the bath of claim 1 and electrodepositing an iron nickel alloy containing about from 5 to about 50% iron onto a cathodic surface.
 22. A process of claim 21, wherein the organic sulfide is selected from the group consisting of an amino thiazole of the structure:
 23. The process of claim 22 wherein R5 and R6 are hydrogen.
 24. The process of claim 22 wherein R9 is lower alkyl sulfonic acid.
 25. The process of claim 22 wherein R9 is lower alkyl carboxy acid and salts thereof.
 26. The process of claim 21 wherein the ratio of nickel ions to iron ions in the bath ranges from about 5 to about 50 to 1; and the ratio of complexing agent to iron ion concentration ranges in the bath from about 3 to about 50 to
 1. 27. The process of claim 21 wherein the total iron ions are present in an amount ranging from about 5 to 40 g/l, calculated as FeSO4.7H2O; nickel sulfate present in an amount ranging from about 40 to 300 g/l, calculated as nickel sulfate.6H2O; nickel chloride hexahydrate present in an amount from about 80 to 250 g/l and the complexing agent is present in an amount from about 10 to 100 g/l.
 28. The process of claim 21 wherein the complexing agent is an aliphatic carboxylic acid having from 1 to 3 carboxyl groups, 2 to 8 carbon atoms, and 1 to 6 hydroxyl groups.
 29. The process of claim 21 wherein the complexing agent contains an amino group.
 30. The process of claim 21 wherein the complexing agent is citric acid.
 31. The process of claim 21 wherein the complexing agent is gluconic acid.
 32. The process of claim 21 wherein the sulfo-oxygen brightener is saccharin.
 33. The process of claim 21 further comprising an acetylenic nickel brightener present in an amount ranging from about 10 to 500 mg/l.
 34. The process of claim 21 further comprising a quaternary nitrogen heterocyclic nickel brightener present in an amount ranging from about 1 to about 50 mg/l.
 35. The process of claim 21 wherein R1 is hydrogen and R2 is nitrogen of an organic radical.
 36. The process of claim 21 wherein R3 is lower alkyl sulfonic acid.
 37. The process of claim 22 wherein R3 is lower alkoxy aryl sulfonic acid.
 38. The process of claim 21 wherein the organic sulfide is 2-aminothiazole in a concentration of about 0.001 to about 0.005 grams/liter.
 39. The process of claim 21 wherein the organic sulfide is isothiourea-s-propionic acid in a concentration of about 0.001 to about 0.010 grams/liter.
 40. The process of claim 21 wherein the organic sulfide is a compound of the formula: 